Scan needle and scan display system including same

ABSTRACT

A scan display system includes a picture receiving unit, a scan needle, a picture display screen having first and second opposing surfaces, and a driving unit. The picture receiving unit is configured to receive picture data and transmit the picture data to the scan needle. The driving unit is configured to perform a picture scanning process by moving the scan needle to scan in a vertical direction relative to the first surface of the picture display screen at a predetermined frequency. The scan needle is configured to emit light, representative of the picture data, to the first surface of the picture display screen to project image lines, each image line being projected by the scan needle during the scan. The picture display screen is configured to receive the emitted light on the first surface and display an image comprising the image lines on the second surface.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a display system and, moreparticularly, to a display system including a scan needle and adisplaying method of the display system.

BACKGROUND

A light emitting diode (LED), which is a kind of semiconductor diode,can convert electrical energy into optical energy, and emit differentlight having different colors depending on a material of a lightemitting layer included in the LED.

A conventional LED display panel is formed by assembling a plurality ofLEDs on a substrate. In order to display an image in a display area ofthe conventional LED display panel, it is necessary to form theplurality of LEDs in the entire display area of the display panel, whichmay require a complicated manufacturing process and a high manufacturingcost. In addition, because the conventional LED display includes a largenumber of LEDs, the conventional LED display has high power consumption.

SUMMARY

According to one embodiment of the present disclosure, a scan displaysystem includes a picture receiving unit, a scan needle, a picturedisplay screen having first and second opposing surfaces, and a drivingunit. The picture receiving unit is configured to receive picture dataand coupled to the scan needle to transmit the picture data to the scanneedle. The driving unit is coupled to the scan needle and configured toperform a picture scanning process by moving the scan needle to scan ina vertical direction relative to the first surface of the picturedisplay screen at a predetermined frequency. The scan needle isconfigured to emit light, representative of the picture data, to thefirst surface of the picture display screen to project image lines, eachimage line being projected by the scan needle during the scan. Thepicture display screen is configured to receive the emitted light on thefirst surface and display an image comprising the image lines on thesecond surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a scan needle, according to an embodiment of thepresent disclosure.

FIGS. 2A and 2B are enlarged top views of a region of the scan needle ofFIG. 1, according to embodiments of the present disclosure.

FIG. 3A is a cross-sectional view of the scan needle along a sectionline B-B′ of FIG. 1, according to an embodiment of the presentdisclosure.

FIG. 3B is a cross-sectional view of the scan needle along a sectionline B-B′ of FIG. 1, according to another embodiment of the presentdisclosure.

FIG. 4 is a top view of a scan needle, according to an embodiment of thepresent disclosure.

FIG. 5 is a schematic view illustrating a scan display system, accordingto an embodiment of the present disclosure.

FIG. 6 is a top view of a scan needle and a picture display screenduring a picture scanning process, according to an embodiment of thepresent disclosure.

FIG. 7 is a top view of a picture display screen with an image displayedthereon during a picture scanning process, according to an embodiment ofthe present disclosure.

FIG. 8 is a schematic view illustrating a scan display system, accordingto an embodiment of the present disclosure.

FIG. 9 is a top view of a picture display screen with an image displayedthereon during a picture scanning process, according to an embodiment ofthe present disclosure.

FIG. 10 is a top view of a scan needle and a picture display screen,during a picture scanning process, according to an embodiment of thepresent disclosure.

FIG. 11 is a top view of a picture display screen with an imagedisplayed thereon during a picture scanning process, according to anembodiment of the present disclosure.

FIG. 12 is a top view of a scan needle and a picture display screenduring a picture scanning process, according to an embodiment of thepresent disclosure.

FIG. 13 is a top view of a picture display screen with an imagedisplayed thereon during a picture scanning process, according to anembodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments,examples of which are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

According to embodiments of the present disclosure, a scan needleincludes a plurality of light emitting pixels for emitting lightrepresentative of each of a plurality of image portions. The lightemitted from the scan needle is caused to move relative to a picturedisplay screen at a predetermined frequency to successively projectimage portions on the picture display screen. As a result, an imageformed by the image portions is displayed on the picture display screen.

FIG. 1 is a top view of a scan needle 100, according to an embodiment ofthe present disclosure. Referring to FIG. 1, scan needle 100 includes asubstrate 102, a first color light emitting pixel array 110 including aplurality of first color light emitting pixels 112 formed on substrate102, a second color light emitting pixel array 120 including a pluralityof second color light emitting pixels 122 formed on substrate 102, and athird color light emitting pixel array 130 including a plurality ofthird color light emitting pixels 132 formed on substrate 102. Firstcolor light emitting pixel array 110 is parallel to second color lightemitting pixel array 120, and second color light emitting pixel array120 is parallel to the third color light emitting pixel array 130.

An X-axis direction illustrated in the figures is defined as ahorizontal direction. A Y-axis direction perpendicular to the X-axisdirection is defined as a vertical direction. A Z-axis direction isperpendicular to the X-axis direction and the Y-axis direction. In thepresent disclosure, the “horizontal direction” and “vertical direction”are used for convenience of explanation, but are not intended to limit aparticular orientation of any component described herein.

In the embodiment illustrated in FIG. 1, each one of first color lightemitting pixel array 110, second color light emitting pixel array 120,and third color light emitting pixel array 130 includes pixels 112, 122,or 132 formed in a single row extending in the horizontal direction (theX-axis direction). First color light emitting pixel array 110, secondcolor light emitting pixel array 120, and third color light emittingpixel array 130 are sequentially arranged in the vertical direction (theY-axis direction).

First color light emitting pixels 112 in first color light emittingpixel array 110 emit light in a first color. Second color light emittingpixels 122 in second color light emitting pixel array 120 emit light ina second color. Third color light emitting pixels 132 in third colorlight emitting pixel array 130 emit light in a third color. The firstcolor, the second color, and the third color are different from eachother.

In the embodiment illustrated in FIG. 1, scan needle 100 furtherincludes light-isolating walls 150 formed on substrate 102.Light-isolating walls 150 are disposed between first color lightemitting pixel array 110 and second color light emitting pixel array120, and between second color light emitting pixel array 120 and thirdcolor light emitting pixel array 130. Light-isolating walls 150 may beformed of any non-transparent material, e.g., non-transparent metal, toisolate the light emitted from first color light emitting pixel array110, second color light emitting pixel array 120, and third color lightemitting pixel array 130.

The first color may be any color selected from red, green, blue, yellow,orange, and cyan, and different from the second and third colors. Thesecond color may be any color selected from green, blue, red, yellow,orange, and cyan, and different from the first and third colors. Thethird color may be any color selected from blue, red, green, yellow,orange, and cyan, and different from the first and second colors. In oneembodiment, each of first color light emitting pixels 112 includes a redlight emitting pixel, each of second color light emitting pixels 122includes a blue light emitting pixel, and each of third color lightemitting pixels 132 includes a green light emitting pixel.

In some embodiments of the present disclosure, a first pitch p1 of firstcolor light emitting pixels 112 (i.e., a distance between centers of twoadjacent first color light emitting pixels 112) in the row of firstcolor light emitting pixel array 110 is less than 5 μm. A second pitchp2 of second color light emitting pixels 122 (i.e., a distance betweencenters of two adjacent second color light emitting pixels 122) in therow of second color light emitting pixel array 120 is less than 5 μm. Athird pitch of third color light emitting pixels 132 (i.e., a distancebetween centers of two adjacent third color light emitting pixels 132)in the row of third color light emitting pixel array 130 is less than 5μm. A first spacing s1 between the first color light emitting pixelarray 110 and the second color light emitting pixel array 120 is lessthan 100 μm. A second spacing s2 between the second color light emittingpixel array 120 and the third color light emitting pixel array 130 isless than 100 μm.

In some embodiments of the present disclosure, first color lightemitting pixels 112 in first color light emitting pixel array 110 areformed to have the same size and the same structure. Second color lightemitting pixels 122 in second color light emitting pixel array 120 areformed to have the same size and the same structure. Third color lightemitting pixels 132 in third color light emitting pixel array 130 areformed to have the same size and the same structure.

In the embodiment illustrated in FIG. 1, scan needle 100 includes all offirst color light emitting pixel array 110, second color light emittingpixel array 120, and third color light emitting pixel array 130.However, the present disclosure is not limited thereto. In alternativeembodiments of the present disclosure (not illustrated), scan needle 100may include only one of first color light emitting pixel array 110,second color light emitting pixel array 120, or third color lightemitting pixel array 130 formed on substrate 102. In still somealternative embodiments of the present disclosure (not illustrated),scan needle 100 may include only two of first color light emitting pixelarray 110, second color light emitting pixel array 120, and third colorlight emitting pixel array 130.

In the embodiment illustrated in FIG. 1, the number of first color lightemitting pixels 112 in first color light emitting pixel array 110 is thesame as the number of second color light emitting pixels 122 in secondcolor light emitting pixel array 120. Further, the number of secondcolor light emitting pixels 122 in second color light emitting pixelarray 120 is the same as the number of third color light emitting pixels132 in third color light emitting pixel array 130.

In the embodiment illustrated in FIG. 1, each one of first color lightemitting pixel array 110, second color light emitting pixel array 120,and third color light emitting pixel array 130 includes pixels 112, 122,or 132 formed in a single row extending in the horizontal direction.However, the present disclosure is not limited thereto. In someembodiments explained in further detail below, at least one of firstcolor light emitting pixel array 110, second color light emitting pixelarray 120, and third color light emitting pixel array 130 may includepixels formed in a two-dimensional array including at least two columnsand two rows.

FIG. 2A is an enlarged top view of a region A of scan needle 100,according to an embodiment of the present disclosure. Referring to FIG.2A, region A of scan needle 100 includes a first color light emittingpixel 112_1, a second color light emitting pixel 122_1, and a thirdcolor light emitting pixel 132_1. Each one of first color light emittingpixel 112_1, second color light emitting pixel 122_1, and third colorlight emitting pixel 132_1 is substantially circular in the top view.The shape of a single light emitting pixel is not limited herein. Thatis, the shape of a single light emitting pixel may be circular, square,rectangular, and so on.

A dimension of a singular light emitting pixel is in the range of the0.5 μm to 50 μm. In one embodiment, a diameter of each one of firstcolor light emitting pixel 112_1, second color light emitting pixel122_1, and third color light emitting pixel 132_1 is substantially thesame, e.g., 0.5 μm to 50 μm. However, the dimensions of the three lightemitting pixels are not limited herein. That is, the dimensions of thethree light emitting pixels 112_2, 122_2, and 132_2 may be the same aseach other, or may be different from each other.

FIG. 2B is an enlarged top view of a region A of scan needle 100,according to another embodiment of the present disclosure. Referring toFIG. 2B, region A of scan needle 100 includes a first color lightemitting pixel 112_2, a second color light emitting pixel 122_2, and athird color light emitting pixel 132_2. Each one of first color lightemitting pixel 112_2, second color light emitting pixel 122_2, and thirdcolor light emitting pixel 132_2 is substantially rectangular in the topview. A size along the horizontal (X-axis) direction of first colorlight emitting pixel 112_2, second color light emitting pixel 122_2, andthird color light emitting pixel 132_2 is substantially the same, e.g.,0.5 μm to 50 μm. A size of first color light emitting pixel 112_2 alongthe vertical (Y-axis) direction is, e.g., 0.5 μm to 50 μm. A size ofsecond color light emitting pixel 122_2 along the vertical direction is,e.g., 0.5 μm to 50 μm. A size of third color light emitting pixel 132_2along the vertical direction is, e.g., 0.5 μm to 50 μm.

In one embodiment, an area of first color light emitting pixel 112_2 islarger than an area of second color light emitting pixel 122_2, and anarea of second color light emitting pixel 122_2 is larger than an areaof third color light emitting pixel 132_2. However, the areas of thethree light emitting pixels are not limited herein. That is, the areasof the three light emitting pixels 112_2, 122_2, and 132_2 may be thesame as each other, or may be different from each other.

FIG. 3A illustrates one configuration of scan needle 100, as a scanneedle 100 a shown in a cross-sectional view along a section line B-B′of FIG. 1, according to an embodiment of the present disclosure.Referring to FIG. 3A, scan needle 100A includes a first color lightemitting pixel 112_3A in first color light emitting pixel array 110, asecond color light emitting pixel 122_3A in second color light emittingpixel array 120, and a third color light emitting pixel 132_3A in thirdcolor light emitting pixel array 130 arranged side-by-side on substrate102. First color light emitting pixel 112_3A comprises a first colorlight emitting diode, and is referred to herein as first color lightemitting diode 112_3A. Second color light emitting pixel 122_3Acomprises a second color light emitting diode, and is referred to hereinas second color light emitting diode 122_3A. Third color light emittingpixel 132_3A comprises a third color light emitting diode, and isreferred to herein as third color light emitting diode 132_3A.

Although FIG. 3A illustrates that first color light emitting diode112_3A, second color light emitting diode 122_3A, and third color lightemitting diode 132_3A are arranged in the vertical (Y-axis) direction,the present disclosure is not limited therefore. In some alternativeembodiments, first color light emitting diode 112_3A, second color lightemitting diode 122_3A, and third color light emitting diode 132_3A maybe arranged in the horizontal (X-axis) direction.

As illustrated in FIG. 3A, first color light emitting diode 112_3Aincludes, at least, a first segment 301_1 of a first metal layer and afirst segment 302_1 of a first color light emitting layer, in an orderfrom bottom to top as viewed in FIG. 3A. Second color light emittingdiode 122_3A includes, at least, a second segment 301_2 of the firstmetal layer, a second segment 302_2 of the first color light emittinglayer, a first segment 303_1 of a second metal layer, and a firstsegment 304_1 of a second color light emitting layer, in an order frombottom to top as viewed in FIG. 3A, and at least one first electricalconnector 307. The second segment 301_2 of the first metal layer and thefirst segment 303_1 of the second metal layer are electrically connectedwith each other by the at least one first electrical connector 307.Third color light emitting diode 132_3A includes, at least, a thirdsegment 301_3 of the first metal layer, a third segment 302_3 of thefirst color light emitting layer, a second segment 303_2 of the secondmetal layer, a second segment 304_2 of the second color light emittinglayer, a third metal layer 305, and a third color light emitting layer306, in an order from bottom to top as viewed in FIG. 3A, and at leastone second electrical connector 308. The third segment 301_3 of thefirst metal layer, the second segment 303_2 of the second metal layer,and third metal layer 305 are electrically connected with each other bythe at least one second electrical connector 308.

Scan needle 100A also includes an insulating layer 310 and a transparentconductive layer 320 covering first color light emitting diode 112_3A,second color light emitting diode 122_3A, and third color light emittingdiode 132_3A. Insulating layer 310 is formed with openings exposingportions of the top surfaces of first segment 302_1 of the first colorlight emitting layer, first segment 304_1 of the second color lightemitting layer, and third color light emitting layer 306. Transparentconductive layer 320 covers insulating layer 310 and is formed in theopenings of insulating layer 310, thereby contacting the exposed topsurfaces of first segment 302_1 of the first color light emitting layer,first segment 304_1 of the second color light emitting layer, and thirdcolor light emitting layer 306 via the openings.

Scan needle 100 further includes light-isolating walls 350 arrangedbetween first color light emitting diode 112_3A and second color lightemitting diode 122_3A, and between second color light emitting diode122_3 and third color light emitting diode 132_3. The height oflight-isolating walls 350 may be greater than the highest one of firstcolor light emitting diode 112_3, second color light emitting diode122_3, and third color light emitting diode 132_3. In the embodimentillustrated in FIG. 3A, the height of light-isolating walls 350 isgreater than the height of third color light emitting diode 132_3.

Moreover, scan needle 100 includes a transparent isolation layer 330covering all of first color light emitting diode 112_3A, second colorlight emitting diode 122_3A, third color light emitting diode 132_3A,insulating layer 310, a transparent conductive layer 320, andlight-isolating walls 350. In addition, microlenses 360 are formed oneach one of first color light emitting diode 112_3A, second color lightemitting diode 122_3A, and third color light emitting diode 132_3A.

Substrate 102 may be an integrated circuit (IC) substrate which includesan interconnection layer electrically connected with the first segmentof first metal layer 301-1 in first color light emitting diode 112_3,the second segment of the first metal layer 301 2 in second color lightemitting diode 122_3, and the third segment of the first metal layer301_3 in third color light emitting diode 132_3. Herein, the ICsubstrate at least includes a drive circuit which separately controlseach of first color light emitting diode 112_3A, second color lightemitting diode 122_3A, and third color light emitting diode 132_3A.

FIG. 3B illustrates another configuration of scan needle 100, as a scanneedle 100B shown in is a cross-sectional view along a section line B-B′of FIG. 1, according to another embodiment of the present disclosure.Elements of scan needle 100B that are the same as those of scan needle100A are identified by the same reference numbers. As illustrated inFIG. 3B, scan needle 100B includes a first color light emitting diode112_3B in first color light emitting pixel array 110, a second colorlight emitting diode 122_3B in second color light emitting pixel array120, and a third color light emitting diode 132_3B in third color lightemitting pixel array 130 arranged side-by-side on substrate 102.

First color light emitting diode 112_3B includes, at least, firstsegment 301_1 of first metal layer and first color light emitting layer302, in an order from bottom to top as viewed in FIG. 3B. Second colorlight emitting diode 122_3B includes, at least, second segment 301_2 ofthe first metal layer and second color light emitting layer 304, in anorder from bottom to top as viewed in FIG. 3B. Third color lightemitting diode 132_3B includes, at least, third segment 301_3 of thefirst metal layer and third color light emitting layer 306, in an orderfrom bottom to top as viewed in FIG. 3B.

Scan needle 100B also includes insulating layer 310 and transparentconductive layer 320 covering first color light emitting diode 112_3B,second color light emitting diode 122_3B, and third color light emittingdiode 132_3B. Insulating layer 310 is formed with openings exposingportions of the top surfaces of first color light emitting layer 302,second color light emitting layer 304, and third color light emittinglayer 306. Transparent conductive layer 320 covers insulating layer 310and is formed in the openings of insulating layer 310, therebycontacting the exposed top surfaces of first color light emitting layer302, second color light emitting layer 304, and third color lightemitting layer 306 via the openings.

Scan needle 100B further includes light-isolating walls 350 arrangedbetween first color light emitting diode 112_3B and second color lightemitting diode 122_3B, and between second color light emitting diode122_3B and third color light emitting diode 132_3B. The height oflight-isolating walls 350 may be greater than the highest one of firstcolor light emitting diode 112_3B, second color light emitting diode122_3B, and third color light emitting diode 132_3B. In the embodimentillustrated in FIG. 3B, first color light emitting diode 112_3B, secondcolor light emitting diode 122_3B, and third color light emitting diode132_B3 have substantially the same height. Thus, the height oflight-isolating walls 350 is greater than all of first color lightemitting diode 112_3B, second color light emitting diode 122_3B, andthird color light emitting diode 132_3B.

Moreover, scan needle 100B includes transparent isolation layer 330covering all of first color light emitting diode 112_3, second colorlight emitting diode 122_3, third color light emitting diode 132_3,insulating layer 310, a transparent conductive layer 320, andlight-isolating walls 350. In addition, microlenses 360 are formed oneach one of first color light emitting diode 112_3, second color lightemitting diode 122_3, third color light emitting diode 132_3.

While FIGS. 3A and 3B illustrate two examples of the structures of thelight emitting pixels, the present disclosure is not limited thereto.First color light emitting pixels 112, second color light emittingpixels 122, and third color light emitting pixels 132 may be formed inany structure that can respectively emit light in the first color,second color, and third color.

FIG. 4 is a top view of a scan needle 400, according to an embodiment ofthe present disclosure. Referring to FIG. 4, scan needle 400 includes asubstrate 402, a first color light emitting pixel array 410 including aplurality of first color light emitting pixels 412 formed on substrate402, a second color light emitting pixel array 420 including a pluralityof second color light emitting pixels 422 formed on substrate 402, and athird color light emitting pixel array 430 comprising a plurality ofthird color light emitting pixels 232 formed on substrate 402. Firstcolor light emitting pixel array 410 is parallel to second color lightemitting pixel array 420, and second color light emitting pixel array420 is parallel to the third color light emitting pixel array 430.

Each one of first color light emitting pixel array 410, second colorlight emitting pixel array 420, and third color light emitting pixelarray 430 includes pixels formed in a two-dimensional array (i.e., amatrix) having at least two rows extending in the horizontal directionand at least two columns extending in the vertical direction as viewedin FIG. 4.

In the embodiment illustrated in FIG. 4, scan needle 400 furtherincludes light-isolating walls 450 formed on substrate 402.Light-isolating walls 450 are disposed between first color lightemitting pixel array 410 and second color light emitting pixel array420, and between second color light emitting pixel array 420 and thirdcolor light emitting pixel array 430. Light-isolating walls 450 may beformed of any non-transparent material, e.g., non-transparent metal, toisolate the light emitted from first color light emitting pixel array410, second color light emitting pixel array 420, and third color lightemitting pixel array 430.

In the embodiment illustrated in FIG. 4, each one of first color lightemitting pixel array 410, second color light emitting pixel array 420,and third color light emitting pixel array 430 is a 18×2 array including18 columns each extending in the vertical direction and 2 rows eachextending in the horizontal direction. In some alternative embodimentsof the present disclosure, each one of first color light emitting pixelarray 410, second color light emitting pixel array 420, and third colorlight emitting pixel array 430 may be a 4000×50 array including 4000columns each extending in the vertical direction and 50 rows eachextending in the horizontal direction.

In some embodiments of the present disclosure, a first pitch p1 of firstcolor light emitting pixels 412 (i.e., a distance between centers of twoadjacent first color light emitting pixels 412) in both the horizontaldirection and the vertical direction is less than 5 μm. A second pitchp2 of second color light emitting pixels 422 (i.e., a distance betweencenters of two adjacent second color light emitting pixels 422) in boththe horizontal direction and the vertical direction is less than 5 μm. Athird pitch of third color light emitting pixels 432 (i.e., a distancebetween centers of two adjacent third color light emitting pixels 432)in both the horizontal direction and the vertical direction is less than5 μm. A first spacing s1 between the first color light emitting pixelarray 410 and the second color light emitting pixel array 420 is lessthan 100 μm. A second spacing s2 between the second color light emittingpixel array 420 and the third color light emitting pixel array 430 isless than 100 μm.

An aspect ratio of a light emitting pixel array is defined herein as aratio of a width of the light emitting pixel array (i.e., a size of alonger side of the light emitting pixel array) to a length of the lightemitting pixel array (i.e., a size of a shorter side of the lightemitting pixel array). According to some embodiments of the presentdisclosure, an aspect ratio of first color light emitting pixel array410 is not less than 10:1. According to an alternative embodiment of thepresent disclosure, an aspect ratio of first color light emitting pixelarray 410 is not less than 100:1.

In some embodiments of the present disclosure, a total size of scanneedle 400 along the vertical direction is not more than 1 mm. In someembodiments of the present disclosure, a total aspect ratio of scanneedle 400 is not less than 3:1.

In scan needles according to some embodiments of the present disclosure,at least one of the first color light emitting pixel array, the secondcolor light emitting pixel array, and the third color light emittingpixel array may be formed as a single row, and at least one of theremaining first color light emitting pixel array, second color lightemitting pixel array, and third color light emitting pixel array may beformed as a two-dimensional array. For example, a scan needle mayinclude a first color light emitting pixel array formed as a single row,and a second color light emitting pixel array and a third color lightemitting pixel array each formed as a two-dimensional array.

In some embodiments, the total area of first color light emitting pixelarray 410 may be the same as the total area of second color lightemitting pixel array 420, and the total area of second color lightemitting pixel array 420 may be the same as the total area of thirdcolor light emitting pixel array 430.

FIG. 5 is a schematic view illustrating a scan display system 500,according to an embodiment of the present disclosure. Referring to FIG.5, scan display system 500 includes a picture receiving unit 510, a scanneedle 520, a picture display screen 530 having first and secondopposing surfaces 531 and 532, and a driving unit 540.

Picture receiving unit 510 is configured to receive picture data and iscoupled to a drive circuit (e.g., a drive circuit formed in substrate102 illustrated in FIG. 3) of scan needle 520 to transmit the picturedata to the drive circuit of scan needle 520. Scan needle 520 isconfigured to be driven by the drive circuit to emit light 550,representative of each of a plurality of portions of an image(hereinafter referred to as “image portions”), and to successivelyproject light 550 representative of the plurality of image portions tofirst surface 531 of picture display screen 530. Picture display screen530 is configured to receive the emitted light 550 on first surface 531and display the image portions on second surface 532. Driving unit 540is coupled to scan needle 520 and configured to perform a picturescanning process by moving scan needle 520 to scan in the verticaldirection relative to first surface 531 of picture display screen 530 ata predetermined frequency, such that the plurality of image portionsdisplayed on second surface 532 of picture display screen 530 aresuccessively arranged along the vertical direction of picture displayscreen 530. The predetermined frequency may be not less than 10 Hz. Inother words, a time interval for a repeated occurrence of an imageportion at a position on picture display screen 530 may be less than 0.1s. As a result of the persistence of vision phenomena (when an imageseen by the human eye disappears, the human eye can continue to retainthe image for about 0.1 s to 0.4 s), picture display screen 530 displaysan image including the plurality of image portions on second surface532.

FIG. 6 schematically illustrates scan needle 520 and picture displayscreen 530 during a picture scanning process as viewed along the Z-axisdirection from a front side of picture display screen 530 and facingsecond surface 532 of picture display screen 530, according to anembodiment of the present disclosure. For the convenience of describingthe relative positions of scan needle 520 and picture display screen530, picture display screen 530 is illustrated as transparent in FIG. 6to show scan needle 520 arranged behind picture display screen 530.

As shown in FIG. 6, scan needle 520 includes a first color lightemitting pixel array 522 including a plurality of first color lightemitting pixels (not illustrated), a second color light emitting pixelarray 524 including a plurality of second color light emitting pixels(not illustrated), and a third color light emitting pixel array 526including a plurality of third color light emitting pixels (notillustrated). First color light emitting pixel array 522, second colorlight emitting pixel array 524, and third color light emitting pixelarray 526 are parallel to each other and sequentially arranged along thevertical direction.

FIG. 7 schematically illustrates picture display screen 530 with animage 700 displayed on second surface 532 during a picture scanningprocess, according to an embodiment of the present disclosure.

Referring to FIGS. 5, 6, and 7, during the picture scanning process,scan needle 520 is driven by driving unit 540 to move in the verticaldirection relative to first surface 531 of picture display screen 530.At an initial time point t1 during the picture scanning process, scanneedle 520 is located at an initial position and projects a first imageportion 710_1 on picture display screen 530 at a first and top-mostposition. At a second time point t2, scan needle 520 is moved down alongthe vertical direction and projects a second image portion 710_2 onpicture display screen 530 at a second position below the firstposition. Image portion 710_2 may be immediately adjacent to imageportion 710_1. Alternatively, a top portion of image portion 710_2 mayoverlap with a bottom portion of image portion 710_1. At a third timepoint t3, scan needle 520 is moved down along the vertical direction andprojects a third image portion 710_3 on picture display screen 530 at athird position below the second position. Image portion 710_3 may beimmediately adjacent to image portion 710_2. Alternatively, a topportion of image portion 710_3 may overlap with a bottom portion ofimage portion 710_2. In this manner, the picture scanning processcontinues with scan needle 520 successively projecting image portions atsuccessive time points until scan needle 520 projects a final imageportion 710_n on picture display screen 530 at a bottom-most position.As a result, a full image 700 formed by image portions 710_1, 710_2,710_3, . . . , and 710_n is displayed on picture display screen 530.Afterwards, scan needle 520 is moved by driving unit 540 back to theinitial position and then projects a series of updated image portions710_1, 710_2, 710_3, . . . , and 710_n on picture display screen 530 todisplay an updated image. The frequency at which scan needle 520 scansis relatively high, so that human eyes will observe a continues image onpicture display screen 530.

FIG. 8 is a schematic view illustrating a scan display system 800according to an embodiment of the present disclosure. Referring to FIG.8, scan display system 800 includes a picture receiving unit 810, a scanneedle 820, a picture display screen 830 having first and secondopposing surfaces 831 and 832, a driving unit 840, and a projection unit850.

Picture receiving unit 810 is configured to receive picture data and iscoupled to the scan needle to transmit the picture data to scan needle820. Scan needle 820 is configured to successively emit light 822,representative of each of a plurality of portions of an image(hereinafter referred to as “image portions”), at successive timepoints. Projecting unit 850 may include a lens or a mirror, and isconfigured to successively project light 822 emitted from scan needle820 representative of the plurality of image portions to first surface831 of picture display screen 830. Picture display screen 830 isconfigured to receive the projected light 822 on first surface 831 anddisplay the image portions on second surface 832. Driving unit 840 iscoupled to projecting unit 850 and configured to perform a picturescanning process by moving the lens or mirror in projecting unit 850 toredirect light 822 projected from projecting unit 820, such that light822 moves in the vertical direction relative to first surface 831 ofpicture display screen 830 at a predetermined frequency. For example,driving unit 840 may be configured to rotate or tilt the lens or themirror included in projecting unit 850 to redirect light 822 emittedfrom scan needle 820 to different positions on first surface 831 ofpicture display screen. As a s result, picture display screen 830displays an image including the plurality of image portions on secondsurface 832.

FIG. 9 schematically illustrates picture display screen 830 with animage 900 displayed on second surface 832 during a picture scanningprocess, according to an embodiment of the present disclosure.

Referring to FIGS. 8 and 9, during the picture scanning process,projecting unit 850 is driven by driving unit 840 to scan light 822 inthe vertical direction relative to first surface 831 of picture displayscreen 830. At an initial time point t1 during the picture scanningprocess, projecting unit 850 is at an initial position to project afirst image portion 910_1 on picture display screen 830 at a first andtop-most position. First image portion 910_1 is light 822 emitted byscan needle 820 and representative of picture data that is projected byprojecting unit 850. At a second time point t2, projecting unit 850 ismoved by driving unit 840 to project a second image portion 910_2 onpicture display screen 830 at a second position below the first positionas viewed in FIG. 9. Image portion 910_2 may be immediately adjacent toimage portion 910_1. Alternatively, a top portion of image portion 910_2may overlap with a bottom portion of image portion 910_1. At a thirdtime point t3, projecting unit 850 is moved by driving unit 840 toproject a third image portion 910_3 on picture display screen 830 at athird position below the second position as viewed in FIG. 9. Imageportion 910_3 may be immediately adjacent to image portion 910_2.Alternatively, a top portion of image portion 910_3 may overlap with abottom portion of image portion 910_2. In this manner, the picturescanning process continues with projecting unit 850 successivelyprojecting image portions at successive time points until projectingunit 850 projects a final image portion 910_n on picture display screen830 at a bottom-most position. As a result, a full image 900 formed byimage portions 910_1, 910_2, 910_3, . . . , and 910_n is displayed onpicture display screen 830. Afterwards, projecting unit 850 is moved bydriving unit 840 to the initial position and projects a series ofupdated image portions 910_1, 910_2, 910_3, . . . , and 910_n on picturedisplay screen 830 to display an updated image.

FIG. 10 schematically illustrates a scan needle 1020 and a picturedisplay screen 1030 during a picture scanning process as viewed alongthe Z-axis direction and facing display screen 1030, according to anembodiment of the present disclosure. For the convenience of describingthe relative positions of scan needle 1020 and picture display screen1030, picture display screen 1030 is illustrated as transparent in FIG.10 to show scan needle 1020 arranged behind picture display screen 1030.

As shown in FIG. 10, scan needle 1020 includes a first color lightemitting pixel array 1022 including a plurality of first color lightemitting pixels (not illustrated), a second color light emitting pixelarray 1024 including a plurality of second color light emitting pixels(not illustrated), and a third color light emitting pixel array 1026including a plurality of third color light emitting pixels (notillustrated). First color light emitting pixel array 1022, second colorlight emitting pixel array 1024, and third color light emitting pixelarray 1026 are parallel to each other and sequentially arranged alongthe horizontal direction.

FIG. 11 schematically illustrates picture display screen 1030 with animage 1100 displayed on a surface during a picture scanning process,according to an embodiment of the present disclosure.

Referring to FIGS. 10 and 11, during the picture scanning process, scanneedle 1020 may be driven by a driving unit (such as driving unit 540 inFIG. 5) to move in the horizontal direction relative to picture displayscreen 1030. At an initial time point t1 during the picture scanningprocess, scan needle 1020 is located at an initial position and projectsa first image portion 1110_1 on picture display screen 1030 at a firstand left-most position. At a second time point t2, scan needle 1020 ismoved along the horizontal direction and projects a second image portion1110_2 on picture display screen 1030 at a second position at a rightside of the first position as viewed in FIG. 11. Second image portion1110_2 may be immediately adjacent to image portion 1110_1.Alternatively, a left portion of image portion 1110_2 may overlap with aright portion of image portion 1110_1. At a third time point t3, scanneedle 1020 is moved further along the horizontal direction and projectsa third image portion 1110_3 on picture display screen 1030 at a thirdposition at a right side of the second position as viewed in FIG. 11.Image portion 1110_3 may be immediately adjacent to image portion1110_2. Alternatively, a left portion of image portion 1110_3 mayoverlap with a right portion of image portion 1110_2. In this manner,the picture scanning process continues with scan needle 1020successively projecting image portions at successive time points untilscan needle 1020 projects a final image portion 1110_n on picturedisplay screen 1030 at a right-most position. As a result, a full image1100 formed by image portions 1110_1, 1110_2, 1110_3, . . . , and 1110_nis displayed on picture display screen 1030. Afterwards, scan needle1020 is moved back to the initial position and projects a series ofupdated image portions 1110_1, 1110_2, 1110_3, . . . , and 1110_n onpicture display screen 1030 to display an updated image.

In some alternative embodiments of the present disclosure (notillustrated), a projecting unit (such as projecting unit 850 in FIG. 8)may be used to project light emitted from scan needle 1020 to picturedisplay screen 1030, and the projecting unit may be driven by a drivingunit (such as driving unit 840 in FIG. 8) to perform a picture scanningprocess to scan the light in the horizontal direction relative topicture display screen 1030. The picture scanning process may be similarto the picture scanning process described with respect to FIGS. 8 and 9,except that the light emitted by scan needle 1020 in the currentembodiment is caused to scan in the horizontal direction instead of thevertical direction. Therefore, a detailed description of thisalternative embodiment is not repeated.

In some alternative embodiments of the present disclosure (notillustrated), a scan needle may not be positioned along the horizontaldirection or the vertical direction with respect to a picture displayscreen. Instead, a side of the scan needle and a side of the picturedisplay screen may form an angle greater than 0 degree and less than 90degree.

FIG. 12 schematically illustrates a scan needle 1220 and a picturedisplay screen 1230 during a picture scanning process as viewed alongthe Z-axis direction and facing picture display screen 1230, accordingto an embodiment of the present disclosure. For the convenience ofdescribing the relative positions of scan needle 1220 and picturedisplay screen 1230, picture display screen 1230 is illustrated astransparent in FIG. 12 to show scan needle 1220 arranged behind picturedisplay screen 1230.

Scan needle 1220 includes only one pixel comprising at least one of afirst color light emitting diode, a second color light emitting diode,and a third color light emitting diode. An aspect ratio of the pixelincluded in scan needle 1220 is not less than 1:3. A size of the pixelin the horizontal direction is not more than 50 μm, and may be in therange of 10 μm to 12 μm. A size of the pixel in the vertical directionis not more than 50 μm, and may be in the range of 10 μm to 30 μm. Inone embodiment, a size of a single light emitting diode is in the rangeof 0.5 μm to 50 μm. A shape of the pixel is circular or rectangular. Insome embodiments, the pixel includes a red light emitting diode, a bluelight emitting diode, and a green light emitting diode. An area of thered light emitting diode is larger than an area of the blue lightemitting diode, and the area of the blue light emitting diode is largerthan an area of the green light emitting diode.

FIG. 13 schematically illustrates picture display screen 1230 with animage 1300 displayed thereon during a picture scanning process,according to an embodiment of the present disclosure.

Referring to FIGS. 12 and 13, during the picture scanning process, scanneedle 1220 may be driven by a driving unit (such as driving unit 540 inFIG. 5) to move in the horizontal direction and in the verticaldirection relative to picture display screen 1230. At an initial timepoint t1 during the picture scanning process, scan needle 1220 islocated at an initial position and projects an image portion 1310_1_1 onpicture display screen 1230 at the left-most position in a first row. Ata second time point t2, scan needle 1220 is moved along the horizontaldirection and projects an image portion 1310_1_2 on picture displayscreen 1230 at a position at a right side of the previous position. Inthis manner, the picture scanning process continues until scan needle1220 projects an image portion 1310_1_m on picture display screen 1230at a top-right position. Then, scan needle 1220 is moved back to theleft in the horizontal direction and moves down in the verticaldirection to project an image portion 1310_2_1 on picture display screen1230 at the left-most position in a second row. The driving unitcontinues to move scan needle 1220 to scan in the horizontal directionto project image portions 1310_2_2, . . . , 1310_2_m in the second rowon picture display screen 1230. The process continues until scan needle1220 projects image portions 1310_n_1, 1310_n_2, . . . , 1310_n_m in abottom row on picture display screen 1230. As a result, a full image1300 formed by image portions 1310_1_1, . . . , and 1310_n_m isdisplayed on picture display screen 1230. Afterwards, scan needle 1020is moved by the driving unit back to the initial position and projects aseries of updated image portions 1310_1_1, . . . , and 1310_n_m onpicture display screen 1230 to display an updated image.

In an alternative embodiment of the present disclosure (notillustrated), a projecting unit (such as projecting unit 850 in FIG. 8)may be used to project light emitted from scan needle 1220 to picturedisplay screen 1230, and the projecting unit may be driven by a drivingunit (such as driving unit 840 in FIG. 8) to perform a picture scanningprocess to scan the light in the horizontal direction and in thevertical direction relative to picture display screen 1230. The picturescanning process may be similar to the picture scanning processdescribed with respect to FIGS. 8 and 9, except that the light emittedby scan needle 1220 in the alternative embodiment is caused to scan inboth the horizontal direction and the vertical direction instead of onlyin the vertical direction. Therefore, a detailed description of thisalternative embodiment is not repeated.

In the above described embodiments of the present disclosure, the scandisplay system includes a scan needle including only three lightemitting pixel arrays, or even fewer than three light emitting pixelarrays. The scan needle has an area less than the total display area ofthe picture display screen. Thus, the scan display system of theembodiments of the present disclosure includes far fewer light emittingpixels than a conventional display system which includes light emittingpixels formed on the entire display area. As a result, a manufacturingprocess may be simplified, manufacturing cost may be reduced, powerconsumption may be reduced, and package size may be reduced.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

What is claimed is:
 1. A scan display system, comprising: a picturereceiving unit; a scan needle; a picture display screen having first andsecond opposing surfaces; and a driving unit, wherein: the picturereceiving unit is configured to receive picture data and coupled to thescan needle to transmit the picture data to the scan needle, the drivingunit is coupled to the scan needle and configured to perform a picturescanning process by moving the scan needle to scan in a verticaldirection relative to the first surface of the picture display screen ata predetermined frequency, the scan needle is configured to emit light,representative of the picture data, to the first surface of the picturedisplay screen to project image lines, each image line being projectedby the scan needle during the scan, and the picture display screen isconfigured to receive the emitted light on the first surface and displayan image comprising the image lines on the second surface; wherein thescan needle includes: a substrate: a first color light emitting pixelarray comprising a plurality of first color light emitting pixels formedon the substrate; a second color light emitting pixel array comprising aplurality of second color light emitting pixels formed on the substrate;and a third color light emitting diode pixel array comprising aplurality of third color light emitting pixels formed on the substrate,the first color light emitting pixel array being parallel to the secondcolor light emitting pixel array, and the second color light emittingpixel array being parallel to the third color light emitting pixelarray, one of the first color light emitting pixels includes a firstsegment of a first color light emitting layer formed on the substrate;one of the second color light emitting pixels includes a second segmentof the first color light emitting layer formed on the substrate and afirst segment of a second color light emitting layer formed over thesecond segment of the first color light emitting layer; and one of thethird color light emitting pixels includes a third segment of the firstcolor light emitting layer formed on the substrate, a second segment ofthe second color light emitting layer formed over the third segment ofthe first color light emitting layer, and a third color light emittinglayer formed over the second segment of the second color light emittinglayer.
 2. The scan display system according to claim 1, wherein: theplurality of first color light emitting pixels in the first color lightemitting pixel array are formed in a single row or in a two-dimensionalarray having at least two rows and two columns; the plurality of secondcolor light emitting pixels in the second color light emitting pixelarray are formed in a single row or in a two-dimensional array having atleast two rows and two columns; and the plurality of third color lightemitting pixels in the third color light emitting pixel array are formedin a single row or in a two-dimensional array having at least two rowsand two columns.
 3. The scan display system according to claim 2,wherein: the first color light emitting pixel array is a 4000×50 array;the second color light emitting pixel array is a 4000×50 array; and thethird color light emitting pixel array is a 4000×50 array.
 4. The scandisplay system according to claim 1, wherein: a pitch of the first colorlight emitting pixels in a row of the first color light emitting pixelarray is less than 5 μm; a spacing between the first color lightemitting pixel array and the second color light emitting pixel array isless than 100 μm; a pitch of the second color light emitting pixels in arow of the second color light emitting pixel array is less than 5 μm; aspacing between the second color light emitting pixel array and thethird color light emitting pixel array is less than 100 μm; and a pitchof the third color light emitting pixels in a row of the third colorlight emitting pixel array is less than 5 μm.
 5. The scan display systemaccording to claim 1, wherein: an aspect ratio of the first color lightemitting pixel array is not less than 10:1; a size of one of the firstcolor light emitting pixels in a row direction of the first color lightemitting pixel array is same as a size of one of the second color lightemitting pixels in a row direction of the second color light emittingpixel array; and the size of the one of the second color light emittingpixels in the row direction of the second color light emitting pixelarray is same as a size of one of the third color light emitting pixelsin a row direction of the third color light emitting pixel array.
 6. Thescan display system according to claim 5, wherein the aspect ratio ofthe first color light emitting pixel array is not less than 100:1. 7.The scan display system according to claim 1, wherein: each of the firstcolor light emitting pixels comprises a first color light emittingdiode; each of the second color light emitting pixels comprises a secondcolor light emitting diode; and each of the third color light emittingpixels comprises a third color light emitting diode.
 8. The scan displaysystem according to claim 1, wherein a total width of the scan needle isnot more than 1 mm.
 9. The scan display system according to claim 8,wherein a total aspect ratio of the scan needle is not less than 3:1.10. The scan display system according to claim 1, wherein: a number ofthe first color light emitting pixels in the first color light emittingpixel array is the same as a number of the second color light emittingpixels in the second color light emitting pixel array; and the number ofthe second color light emitting pixels in the second color lightemitting pixel array is the same as a number of the third color lightemitting pixels in the third color light emitting pixel array.
 11. Thescan display system according to claim 1, wherein a shape of each of thefirst color light emitting pixels, the second color light emittingpixels, and the third color light emitting pixels is circular orrectangular.
 12. The scan display system according to claim 1, wherein:each of the first color light emitting pixels comprises a red lightemitting pixel; each of the second color light emitting pixels comprisesa blue light emitting pixel; and each of the third color light emittingpixels comprises a green light emitting pixel.
 13. The scan displaysystem according to claim 12, wherein: an area of one of the first colorlight emitting pixels is larger than an area of one of the second colorlight emitting pixels; and an area of the one of the second lightemitting pixels is larger an area of one of the third light emittingpixels.
 14. The scan display system according to claim 1, wherein thescan needle further includes: light-isolating walls formed on thesubstrate and between the first color light emitting pixel array and thesecond color light emitting pixel array, and between the second colorlight emitting pixel array and the third color light emitting pixelarray.
 15. The scan display system according to claim 14, wherein aheight of the light-isolating walls is greater than a height of thehighest one of the first color light emitting pixels, the second colorlight emitting pixels, and the third color light emitting pixels. 16.The scan display system according to claim 1, wherein an area of one ofthe first color light emitting pixels is the same as an area of one ofthe second color light emitting pixels, and the area of one of thesecond color light emitting pixels is the same as an area of one of thethird color light emitting pixels.
 17. The scan display system accordingto claim 1, wherein: an area of one of the first color light emittingpixels is larger than an area of one of the second color light emittingpixels; and the area of the one of the second light emitting pixels islarger an area of one of the third light emitting pixels.